Simple trace route with simple ping, almost simply in Swift.
基于 ping 并采用 Swift 构建的简单 traceroute，用于检测客户端与服务主机之间的网络状况。
SimpleTracer.trace(host: testCase.host,
maxTraceTTL: 15) { result in
print(result)
/**
Start tracing www.bearychat.com: 54.223.220.218
#0) 172.25.23.253 5.610 ms 7.405 ms 7.604 ms
#1) 111.202.166.1 5.999 ms 6.257 ms 6.459 ms
#2) 202.106.227.105 8.585 ms 8.883 ms 9.079 ms
#3) 219.232.11.65 6.965 ms * *
#4) 202.96.13.230 12.778 ms 13.112 ms 13.334 ms
#5) 124.65.226.134 7.564 ms 7.923 ms 8.219 ms
#6 * * *
#7 * * *
#8) 54.222.25.140 26.394 ms 26.759 ms 26.997 ms
#9) 54.222.24.176 10.353 ms 10.939 ms 11.384 ms
#10) 54.222.25.33 8.901 ms 9.516 ms 9.934 ms
#11 * * *
#12 * * *
#13 * * *
### Host responsed, latency (ms): 7.927060127258301 ms
#14 Data received, size=64
#14 reach the destination 54.223.220.218, trace completed. It's simple! Right?
***/
}